1. Field
The present application relates generally to the operation of overlay networks, and more particularly, to methods and apparatus for event distribution and routing in peer-to-peer overlay networks.
2. Background
A network in which member nodes obtain services in the absence of server-based infrastructure is referred to herein as a “peer-to-peer” overlay network. In a peer-to-peer overlay, peer nodes cooperate with each other both to provide services and to maintain the network. Peer-to-peer overlay networks can be built on top of an underlying network, such as a network utilizing the Internet Protocol (IP).
Typically, the routing of events on peer-to-peer overlay networks presents trade-offs relating to routing latency, bandwidth utilization, and routing table size. For example, it is desirable to have small latencies when routing events. However, to achieve small latencies may result in large routing tables, which may not fit into the available resources of nodes participating on the overlay network. Furthermore, large routing tables may result in poor bandwidth utilization, since significant bandwidth is needed to communicate the routing tables over the overlay network and any changes that occur over time.
Conventional systems have utilized techniques in an attempt to manage the above mentioned trade-offs. For example, some system utilize very large routing tables, which as stated above, may decrease latency but may also strain or exceed the resources at participating nodes. Other systems utilize special nodes in the overlay network that assume more responsibility for event dissemination. However, the bandwidth requirements on these special nodes are so substantial as to require them to be reasonably provisioned.
Unfortunately, the techniques used by conventional system may result in routing tables on different nodes being inconsistent leading to propagation delays. Also, different routing tables may have different lengths and entries, which may result in different propagation trees to disseminate events from the same event originator. Furthermore, different routing tables may result in “holes” such that some nodes may not receive a disseminated event.
Therefore, it is desirable to have an efficient mechanism for event distribution and routing in peer-to-peer overlay networks that overcomes the problems associated with conventional systems.